Improvement in machines for cutting threads on bolts



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I UNITED STATES TENT (Mnch. I l

W. W. HUBBARD, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN MACHINES FOR CUTTING THREADS ON BOLTS.`

Specication forming part of Letters Patent No. 49,524, dated August 22,y1865. i

To all whom 'it may concern Be it known that I, 'W. W. HUBBARD, ofPhiladelphia,Pennsylvania, have invented certain Improvements inBolt-Cutting Machines; and I do hereby declare the following to be afull, clear, and exact description of the same, reference being had tothe accompanying drawings, and to the letters ofreference markedthereon.

My invention consistsof certain novel mechanism, fully describedhereinafter, for cutting the screw-threads of bolts with rapidity.

In order to enable others skilled in the ait to make and use myinvention, I will now proceed to describe its construction andoperation.

On reference to the accompanying drawings, which form a part of thisspecification, Figure 1 is a sectional elevation of my improvedboltcutting machine; Fig. 2, a plan view, and Figs. 3, 4, and 5 detachedviews.

Similar letters refer to similar parts throughout the several views.

A represents part of the frame of the machine, in which turn any numberof horizontal spindles B. At the outer end of each spindle is acylindrical block or head, C; in which, at

, equal distances from each other, are hung three levers, D D D, each ofthe latter being connected by a link, a, to a sleeve, E, arranged toslide on the shaft B. A pin, c, passes through the sleeve E and througha slot, x, in the shaft, so that the sleeve shall turn with the shaft.Against the piu c bears the inner end of a rod,

` "e, which slides freely in an opening inthe center of the head C. Inthe said sleeve is an an-` nular groove, d, into which project thebranches of a forked lever, F, hinged to a bracket, G.

` Between guides H H, in front of each head a; carriage, I, to ahand-lever, J, at y f which are hung two pawls, f, each of the` attori`being adapted to the teeth of a rack, g,`at,t under side of one of theguides H. Fromt et carriage I a plate, h, projects downward, infwhichplate is an openin g for the admission of afrod, K, the latter beingjointed at its inner end to the lever F and bent at itsouterendy,as\show1n in Fig. 3. To the plate h is securedloneendjof acord, fi, which passes over a pulleyi L, andis secured to a weight, M.In the ca geeIfis an opening in which a onned by adjusting-screws m mand n, and n` the side of this holder opposite the head c is a slot, y,audintoa square a set-screw, p, the cutter being retained with- I in therecess by a clasp or strap, q, whichis caused to bear rmlyagainst thecutter by gib, fr, and key s.

The blank bolt X is placed in the holder N so that its shank shallproject through the slot y and its head rest in the square recess lw.The holder N is then adj usted `so that the shank of the bolt shall bedirectly on a line with the rod e in the head C. The dierent parts ofthe machine are now brought to the position shown in Fig. 1, a rotarymotion is imparted to the shafts B by any suitable system ot gearing,and the carriage I ismoved toward the head C, by operating the leversJand pawls f, until the end of each bolt is introduced between thecutters I. As the cutters are carried round with the head they graduallycut a thread in the end of the boltand draw the latter back until itsend is brought against the end of the rod e. As this rod is forced backby the bolt the sleeve E and lever F are moved away from the head (l,and the levers Dare thus elevated to the position shown in Fig. 3, thecutters being lifted from contact with the bolt and the carriage beingthus atf liberty to be drawn quickly forward by the weight M` As thecarriage approaches the limit of its forward motion the plate hisbrought against the bent end of the rod K, the lever F and y the sleeveK arethus drawn forward, and the levers D are movedto their originalposition,

preparatory to the introduction of another bolt4 into the holder and arepetition of above-described operation. I

It is desirable that a number of spindles, holders, and carriages shouldbe arranged on one frame, as one attendant can attend to the cutting ofthreads of several bolts at one time.

I claim as my invention, and "desire to secure by Letters Patent* 1. Theweight M or its equivalent, combined with the carriage I, and head C,with its levers and cutters, so that the carriage shall be moved I awayfrom thehead as soon as the cutters are raised from the bolt,substantiallyas described.

2.- The screw-cutting dies P, connected to the levers D and renderedadjustable thereon In testimony whereof I have signed my neme to thisspeoieation in the presence of two sub- W. W. HUBBARD. Witnesses:

CHARLES E. FOSTER,

JOHN WHITE.

